Triorganosilyl methyl isothiocyanates



United States Patent TRKURGANOSHJYL METHYL ESGTHIOCYANATES John E. Noll, Monroeville, Pa., assignor to Dow Corning Corporation, Midland, Mich., a corporation of Michigan No Drawing. Application September 7, 1954, erial No. 454,605

3 Claims. (Ci. 260-4482) This invention relates to triorganosilylmethyl isothiocyanates.

It is the object of this invention to prepare novel compositions of matter which are useful for fungicides.

This invention relates to compositions of matter of the formula RsSiCHaNCS in which R is selected from the group consisting of monovalent hydrocarbon radicals and hydrocarbonoxy radicals.

The compositions of this invention may be prepared by two methods both of which involve the use of triorganosilylmethylamines of the formula RsSiCHzNI-Iz where R is as above defined. In both of the methods these amines are reacted with carbon disulfide. In the first method the reaction is carried out in the presence of an alkali metal hydroxide and an alcohol whereupon the product is an alkali metal salt of a dithiocarbamic acid of the formula S RISiCHQNH SM The alkali metal salt is then treated with lead nitrate whereupon the lead salt of a dithiocarbamic acid precipitates. These salts have the formula II (RaSiCHaNHCShPb The lead salts are decomposed by heating to give the corresponding isothiocyanates of the formula RsSiCHzNCS II R SiOH NHCSHNMe:

This material is then reacted with ethylchlorocarbonate to give the desired isothiocyanates.

The triorganosilylmethylamines which are employed as starting materials in the process of this invention are described and claimed in the copending application of John L. Speier, Serial No. 171,551, filed June 30, 1950, now Patent No. 2,73 8,357.

For the purpose of this invention R can be any monovalent hydrocarbon radical such as for example alkyl radicals such as ethyl, methyl and octadeeyl; alkenyl radicals such as vinyl, allyl and decenyl; cycloaliphatic radicals such as cyclohexyl and cyclohexenyl; aryl hydrocarbon radicals such as phenyl, tolyl and Xenyl; and aralkyl radicals such as benzyl. Likewise R can be any hydrocarbonoxy radical of the formula RO in which R is any See monovalent hydrocarbon radical such as those above defined.

The following examples are illustrative only and should not be construed as limiting the invention which is properly defined in the appended claims.

Example 1 30 g. of trimethylsilylmethylamine was dissolved in 200 cc. of ethanol containing 10 g. of sodium hydroxide and 15 g. of carbon disulfide was added to the solution which is maintained at 0 C. On standing, sodium N- tririiethylsilylmethyl dithiocarbamate precipitated in yie d.

A solution of lead nitrate was added to an aqueous solution of the sodium N-trimethylsilylmethyl dithiocarbamate. A yellow solid precipitated. This was the lead salt of the formula 8 (MeaSlCHgNH S):Pb

The lead salt was filtered and heated whereupon it decomposed to give the compound trimethylsilylmethyl isothiocyanate, B. P. 90 C. at 25 mm., 12 1.4984, d4 0.938, specific refraction 0.3128. This material reacted with aniline to give N-phenyl-N'-(trimethylsilylmethyl) thiourea, M. P. 122 to 123 C.

Example 2 Example 3 When octadecylvinylphenylsilylmethylamine is reacted with carbon disulfide in alcoholic sodium hydroxide in the manner of Example 1 and the resulting product is treated with lead nitrate and thereafter heated as shown in that example, the product octadecylvinylphenylsilylmethyl isothiocyanate [(C1aHs7)PhMeSiCH2NCS] is obtained.

Example 4 When dimethylphenoxysilylmethylamine is reacted with carbon disulfide and trimethylamine in benzene solution and thereafter with ethyl chlorocarbonate in accordance with the method of Example 2 the compound dimethylphenoxysilylmethyl isothiocyanate [Mez PhO) SiCHzNCS] is obtained.

That which is claimed is:

1. Compounds of the formula RaSiCHzNCS in which R is selected from the group consisting of alkyl and alkoxy radicals.

2. Trimethylsilylmethyl isothiocyanate.

3. Triethoxysilylmethyl isothiocyanate.

References Cited in the file of this patent Cooper: Jour. Am. Chem. Soc., vol. 76 (1954), pages 2499, 2500, efiective date December 29, 1953. 

1. COMPOUNDS OF THE FORMULA R3SICH2NCS IN WHICH R IS SELECTED FROM THE GROUP CONSISTING OF ALKYL AND ALKOXY RADICALS. 